In the related art, there is redundant arrays of inexpensive disks (RAID) technology in which a combination of multiple storage devices are operated as a virtual disk. Disks, which are formed by RAID levels higher than or equal to RAID 1, have redundancy, and even if several storage devices malfunction, data can be recovered from other storage devices. In contrast, in a state where redundancy is lost, and one or more storage devices malfunction, in a so-called multi-dead state, data may not be recovered. Some storage devices may have a self-monitoring, analysis and reporting technology (SMART) function as a function for predicting a malfunction caused by degradation over time.
According to related technology in the related art, self-monitoring, analysis and reporting technology (SMART) data may be requested from one disk among a redundant array of multiple disks. There is technology in which SMART information regarding data disks and a spare disk is obtained, it is predicted if there are any data disks which are highly likely to malfunction among the data disks, and data of a data disk, which is highly likely to malfunction, is copied onto the spare disk.